The importance of the role of conformation in the biological function of proteins and nucleic acids has become increasingly evident in the past few years. Studies will be conducted on selected materials and models of these biological macromolecules. Research will be focused on methods for determining the absolute conformation and conformational transitions in poly-alpha-amino acids (protein models) and polynucleotides (nucleic acid models). Physical methods, such as optical rotatory dispersion, circular dichroism, tritium exchange, and fluorescence will be exploited. Immunological studies will be carried out with synthetic polypeptides to probe the dependence of anti-genicity upon conformation. A study of the interaction between these model polypeptides and polynucleotides will be made to investigate how their conformational states are interdependent, to simulate nucleoprotein complexes. Studies will be conducted on nucleoproteins to investigate how the various histone fractions interact with DNA and what conformational consequences result. Model histones will be synthesized, e.g., ordered sequence polypeptides such as lys, ala, gly, and their interaction with polynucleotides and DNA studied. Thus, the requirements for specific interactions of amino acid chains for the nucleic acid bases will be elucidated. Such studies will perhaps lead to the understanding of how nucleoproteins are involved in control of genetic expression and how aberrations in control mechanisms operate. BIBLIOGRAPHIC REFERENCES: Edith Ong and Gerald D. Fasman. Chromatin Models: Thermal Denaturation Studies of (Lysx, Leuy)n and (Lys)n (Leu)m: DNA Complexes. Biochemistry 15, 477 (1976). Edith C. Ong, Christopher Snell and Gerald D. Fasman. Chromatin Models. The Ionic Strength Dependence of Model Histone-DNA Interactions: Circular Dichroism Studies of Lysine-Leucine Polypeptide: DNA Complexes. Biochemistry 15, 468(1976).